Eric Edstrom
Edstrom IndustriesContents: Water shortages - Water source variations - Water Quality Testing
Preventing Animal Drinking Water Emergencies
• Water Shortages
• Water source quality variation
• Bacteria contaminationAnimal drinking water is subject to many different kinds of emergencies, from water shortages, to contaminated water supplies, to bacteria outbreaks. To protect research and research animals, facilities need to make provisions:
– Prevent these problems in the first place
– Resolve the problems when they occur
Water shortages
• Mechanical failure between supply and facility
• Power failure takes out pumps
Preventing water shortages
• Pumps and purification systems on backup power
• Bypass valves on purification systems
• Store a few days supply of water
• Consider locating storage upstairs so gravity can feed system
• Calculate daily water usage
• With automated watering, remember you may have flushing systems
• Have a minimum of one day’s worth of water in storage
The water source quality is variable. In 1993, Milwaukee learned a valuable if painful lesson. Unusually high rainfall resulted in more run-off into the water supply. In any location, variations in rainy seasons and drought will affect incoming water quality. Facilities should employ water purification like RO to eliminate these variations and provide a standard water quality level all year.
Milwaukee 1993
Cryptosporidium
400,000 people infected
4,000 hospitalized
over 50 deaths
Photo Credit: H.D.A Lindquist, U.S. EPA
EPA standards
55,000 community water supplies
4,769 or 8.6% were in violation of one or more drinking water standardThese statistics were from the www.epa.gov website from a 1996 survey.
Dealing with water source variations
Water purification
Reverse Osmosis
Contaminants Standard CA
Membrane
MembraneDissolved ions >93% Particles 99% >2000MW Bacteria >99% Organics >99% Pyrogens >99%
Once the water is past the purification process, regular testing for bacteria and other contaminants is still important. It can detect systemic problems, failing purification systems or reveal system design problems that need correcting.
• The Guide: “clean potable water”
• Set your own standard
• Quarterly testing
– Bacteria counts (Pseudomonas)
– Coliforms
– Metals
Bacteria Contamination Mittleman published a series of papers in the journal Microcontamination about bacterial contamination in purified water systems. What he found was that bacteria could survive, and in fact thrive even in pure water. The reason for this is bacteria’s tendency to attach to piping surfaces and for biofilms, which in turn secrete a slime that protects them. Bacteria like Pseudomonas Aeruginosa are particularly adept at forming biofilms and surviving in low-nutrient environments.
The table in this slide shows a purified water system innoculated with bacteria. The total plate counts show high bacteria levels around 10,000 cfu/mL. Mittleman then applied a biocide, which resulted 2 days of zero bacteria counts. But on the third day, the bacteria had reappeared and quickly reestablished themselves.
Virtually all free floating bacteria have detached from a biofilm, so it is important to understand that unless measures are taken to control and minimize the biofilm, bacteria counts will be high and quite variable depending upon the frequency of biofilm detachment.
EPA has no standard for Pseudomonas Aeruginosa
Dealing with Bacteria contamination
• Remove most with Reverse Osmosis
• Flushing-based distribution systems require low level disinfectant like chlorine (2-3ppm)
• Testing
Conclusion
• Calculate daily water usage
• Purify your water with Reverse Osmosis
• Test your water quality regularlyReal Life Disasters - Disaster Planning - Facility Planning - Assets Protection - Web Links - Home
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